Air purger



All@ 17, 1943. R. E. wALTERs i 2,327,081

AIR PURGER I Filed Nov. 6, 1941 205605 E. um 75x25 I N V E N TO R ATTORNEYS Patented Aug. 17, 1943 UNITED STATES PATENT OFFICE AIR PURGER Roscoe E. Walters, Oklahoma City, Okla.

Application November 6, 1941, Serial No. 417,977

9 Claims.

#This invention relates to an invention in the art of mechanical refrigeration and more particularly to an improved apparatus Yfor automatically and continuously purging Vnon-condensing gases from mechanical refrigeration systems,

As is well known to those familiar with the art the accumulation of air and other non-condensible gases in any refrigeration system seriously reduces its eiliciency. The'present practice of periodically blowing off suchgases is impractical and inefiicient because it results in the loss of a considerable amount of the refrigerating fiuid from the system, and because it requires so much attention on the part of the operator. l Y f It is the chief object of this invention, therefore, to provide an apparatus which not only continuously and automatically purges such systems of non-condenslble gases, but which simultaneously separates the non-condensible vgases fromfthe refrigerant gas, liquefles the latter, and automatically and continuously Ydeliversthe liquefied refrigerant back into the refrigerating system proper. A

Another object is to provide a purger of this class which is so-designed that it will continue to operate after the refrigerant compressor has been shut off.

A third important object 'of the invention is to provide a purger which is so designed that there is no possibility ofthe high and low pressure lines of the refrigerant system becoming even momentarily or accidentally connected together.

'Ihe detailsof the construction of the invention, together with other objects attending its production will be better understood from the following description when read in connection with the accompanying drawing, which is submitted for illustrative purposes only.

In the drawing the apparatus embodying the invention is shown for the most part in vertical section, and the apparatus is shown in operative association with certain portions of a refrigeration system.

It should be pointed out that the invention will operate equally well regardless of the particular type of refrigerating fluid used by the plant in which the invention is installed. The term ammonia, as used in the following description, is not in any sense a limiting term, but is employed simply to facilitate the description.

Referring now to the apparatus shown in the drawing, the numeral designates a closed tank.

Within the tank is a cooling or condensing coil 6. The lower end of this coil passes through the bottom of the tank and is connected directly with a liquefied ammonia supply line 'I, while the upper end of this coil 6 is similarly connected directly to a suction line 8 which in turn is connected to the intake or suction side of the refrigeration system compressor (not shown). An expansion valve S in the line 1 controls the flow of ammonia into the coil, while a suction valve I0 controls the flow of ammonia gas out of the coil 6,

As a means of continuously maintaining a sufficiently large air space above the ammonia which is liqueed within the tank 5, an overfiowline II is provided. This line affords openv communication between the tank 5 and the lower end of an ammonia receiver tank I2, such receiverl tanks being common to all refrigerating systems. Cut off valves I3 and I4 are inserted in this line simply to facilitate the cleaning and draining of various parts of the system. As shown, the receiver tank is preferably on a lower level 'than the rest of the refrigerating system to facilitate the gravity drainage of liquefied ammonia into the tank.

As a means of introducing the vaporized ammonia and mixed foreign non-condensible gases into tank 5, I`provide a pipe line I5, one end of which is in open communication with the extreme lower end of the tank, and the other end of which is in open communication with al1 the condensers (not shown) of the refrigerating system. A shut off valve I6 is inserted in this line I5, and a short pipe line I'I with a shut oil valve I8 connects the line I5 with the overflow line Il. The valve I8 is normally closed, but when opened it serves to drain all the liquefied ammonia from the tank 5 into the receiver tank I2. At some point above the upper end of the overflow line II, an ammonia gas line I9 cuts into the line I5, and connects this line I5 with the extreme upper end of the receiver tank I2. This line I9 is also preferably provided with a cut off Valve 20, and serves to conduct any vaporized ammonia and mixed non-condensible gases which may accumulate in the top of the receiver tank into the tank 5 where it may also be deaerated or purged of air and other noncondensible gases before returning to the receiver.

As an outlet for the air and other non-condensible gases which are separated from the vaporized ammonia within the tank 5, I provide a pipe line 2| which preferably conducts such gases from the extreme top of the tank 5 to a point Well below said top, and preferably discharges the gases under the surface of water 22 in a bucket 23, or other receptacle. The release oi such gases under Water serves two purposes. It helps to maintain a slight back pressure Within the tank 5, and it serves to notify the attendant or operator of the system whether or not ammonia is escaping from the tank 5 alone with rlDn-condensible eases.- When new condensible gases alone are escaping, the Water in the receptacle simply bubbles. When ammonia is escaping, its release into the water pro..- duces a cracking sound. A control or purge valve 24 is inserted in the line 2l to regulate the ow f gases from the upper end of the tank 5. This valve also helps to maintain a slight back pressure within the tank 5.

As a means of apprising the operator .of the exact liquid level of the liquefied ammonia within the teck l provide ordinary gage glass 2,5 which extends both above and below the level. of the upper end of the overflow line Il. Valves 2 6 and 2 are arranged at the upper and loivcr ends. respectively of this rese glass.

The operation of the invention when used in connection with a refrigeration system is as follows:

Valves lll, I3, 4, l5, 2B, 26 and 21 are opened wide. Valves I and 2,4 are closed, and valve 8 i5 barely cracked. The extreme low pressure created by the compressor on the coil side of valve S causes rapid vapori/tation and expansion of the minute quantity of liquid ammo-nia which passes through this valve. The expansion of the gas with-in the coil c ocls the coil to such an extent that it maintains the interior of the tank at a temperature below the liquefying temperature of the ammonia, i. ger-23 F. at atmospheric pres.- sure.

As the miXed gases new freely from the con.- deIlSers and/or from the receiver 0f the refrigerating system thru pipe lines l5 and I9 and into the bottom of Vthe tank 5, the low temperature therein quickly condenses or liquees the vaporized ammonia, and the non-condensible gasesV accumulate in the top of tank 5 above this liquid.

After the system has been in operation a short time the valve 2 4 is barely cracked so as to per mitl only an extremely small flow o f non-condene. sible gas from the tank 5 to the atmosphere through the water in container 23. The incoming gases must rise through the liquid ammonia in the bottom of tank 5., and this further aids in lioueiyins the vanorized ammonia. By allowing only avery minute now of non-condensiblc gases from the tank, the vaporized ammonia is held in the tank for a suilicient time to liquefy all of it. As` liquid ammonia accumulates in the. tank 5 it everows through line H into. thel receiver tank. 2..

This flow ofY eases into the tank and liquid' and gas out of the tank Continues so long as the refrigeration system is` in operation. When the. compressor ceases to operate. sas continues t0 expand within the. coil; i so 1011s as there is any liquid. refrigerant in. the receiver, so that the cooling effect. continues. within the tank 5 lens after the compressor is shut dow-rt. and consequently there is no, loss of vapor-ized ammonia thru the line 2 I.

In case the refrigeration plant is to be shut down, and is to. remain out of operation for a number of days, the valve 24 should be closed to prevent loss of refrigerant from the system. M;

any time it is desired to drain the tank 5, it 1s only necessary to open the valve I8, and the liquid will drain into the receiver tank I2.

From the above description it will be seen that I have produced a device which will continuously separate and purge non-condensible gases from a refrigerating system without attendant loss of refrigerant and Without requiring constant attention on the part of an operator, and which will also continuously deliver the refrigerant which is separated from the non-condenslble gases 4back into 4the refrigerating system, also ywithout any attention being given to it by an operator.

While I have described and illustrated one speciffic embodiment `of my invention, I am aware that it may be embodied in other forms, and I do :not Wish t9 be limited except by the prior art and by the scope of .the appended claims.

I claim:

i. The combination with a. refrigeration systern which includes s. compressor, refrigerant condensers, and a refrigerant receiver tank. of: a. gas receiver tank having a cooling coil therein; an open gas line connecting the tops of said con densers with the interior of said gas receiver tank; an open overflow line affording flow of liquid refrigerant from an intermediate level within said gas receiver tank into the lower end of said refrigerant receiver tank; and a valved line affording a desired escape of sas from the upper interior of said gos receiver tank.

2V. The combination with a mechanical refrigerating system which includes a compressor, rofrigerant condensers, and a refrigerant receiver tank, of: a gas receiver tank; an open gas line connecting the tons of the condensers with the lower end of said gas receiver tank; a cooling `coil within said gasreceiver tank; an overflow line affording gravity owfof liquid refrigerant from an intermediate level within said sas receiver tank to the bottom of said refrigerant receiver tank; and an adjustable outlet anordins escape for non-condensible .Bases which accumulate Within the upper end of said zas receiver tank.

3. The combination with a refrigeration system which includes a compressor. refrigerant condensers, and a refrigerant receiver tank, of: a gas receiver tank located on a higher level than said refrigerant receiver tank; means in side the gas receiver tank for Vxnaintainlnl its interior at a temperature belowV the lquefyins temperature of the refrigerant used in the S38- tem; a normally open gas line connecting tho tops of said condensers with the lower interior of said gas receiver tank; a. normally open overow line affording gravity flow of liquelled refrigerant from an intermediate level within said gas receiver tank to the lower interior of said refrigerant receiver tank and a valved outlet affording a desired escape of gases from the upper interiorv of said gas receiver tank to the atmos-V phere.

4. The combination with a refrigeration system which includes a compressor, refrigerant condensers, and a. refrigerant receiver tank, of: a gas receiver tank. located on a. higher level than said refrigerant receiver tank; means inside the gas. receiver tank formaintalnlng its interior at a temperature below the liquefying temperature of the. refrigerant used inthe system; a. normnlly open gas line connecting the topsy of said oondensers with. the lower interior of said gas reeeiver tan-k; a normally open overflow line aifording gravity flow of liquefied refrigerant from an intermediate level Within said gas receiver tank to the lower interior of said refrigerant receiver tank; an open line connecting the upper interior of said refrigerant receiver tank with said normally open gas l-ine at an elevation above the upper end of said open overflow line; and a valved outlet affording a desired escape of gases from the upper interior of said gas receiver tank to the atmosphere.

5. The combination with a mechanical refrigeration system Which includes a compressor, a refrigerant receiver tank, and condensers, of: a gas receiver tank; a coil within said gas receiver tank for cooling the interior thereof, said coil being inserted between a source of liquid refrigerant and the suction side of said compressor; an open line for conducting gas from said condensers into the lower end of said gas receiver tank; a liquid refrigerant overflow line for continuously conducting liquid refrigerant from an intermediate level in said gas receiver tank to the lower end of the refrigerant receiver tank by gravity; and an adjustable fiow line for conducting non-condensible gases from the upper end of said gas receiver tank to the atmosphere.

6. The combination with a refrigeration system which includes a compressor, refrigerant condensers, and a refrigerant receiver tank, of a gas receiver tank having a cooling coil therein; an open gas line connecting the tops of said condensers with the interior of said gas receiver tank; an open overflow line affording flow of liquid refrigerant from an intermediate level within said gas receiver tank into the lower end of said refrigerant receiver tank; and a valved line affording a continuous escape of gas from the upper interior of said gas receiver tank.

7. The combination with a refrigeration system which includes a compressor, refrigerant condensers, and a refrigerant receiving tank, of: a gas receiver tank; a cooling coil in the last mentioned tank; a normally open gas line connecting the tops of said condensers with the interior of said gas receiver tank; means for accumulating a body of liquefied refrigerant in the bottom of the gas receiver tank; and means providing continuous escape of non-condensed gases from the upper portion of said gas receiver tank.

8. The combination with a refrigeration system which includes a compressor, refrigerant condensers, and a refrigerant receiving tank, of: a gas receiving tank; a cooling coil within the last mentioned tank; means for constantly maintaining a, body of liquefied refrigerant Within the bottom portion of said gas receiving tank; a normally open gas line connecting the tops of said condensers with the bottom of said gas receiver tank, whereby gases from the condensers must pass through the body of liquefied refrigerant in reaching the upper portion of the gas receiver tank; and means for providing escape of non-condensed gases from the upper portion of said gas receiver tank.

9. The combination with a refrigeration system which includes a compressor, refrigerant condensers, and a refrigerant receiving tank, of: a gas receiving tank; a. cooling coil within the last mentioned tank; means Vfor constantly maintaining a body of liquefied refrigerant Within the bottom portion of said gasV receiving tank; a normally open gas line connecting the tops of said condensers with the bottom of said gas receiver tank, whereby gases from the condensers must pass through the body of liquefied refrigerant in reaching the upper portion of the gas receiver tank; and means for providing continuous escape of non-condensed gases from the upper portion of said gas receiver tank.

ROSCOE E. WALTER-S 

